String instruments emit sound generated by the vibration of one or more strings caused either by bowing (string instruments such as violins), striking ( such as seen in a piano), plucking  (seen in guitars and similar). They are divided in:

Plucked Instruments

• Classic guitar
• Folk guitar
• Semiacoustic guitar (arch top, hollowbody)
• Electric guitar (flat top, carvedtop, neckthru, bolt-in, bolt-on, etc.)
• Electric and Acoustic Bass
• Ethnic and Popular instruments (mandolin, sitar, banjo, liuto, etc.)
• Spinetta

Bowed Instruments

• Violin
• Viola
• Cello
• Double bass

We will be mainly going over guitars, dividing them into three fundamnetal models

Classic guitar

Aesthetically, it’s made up of two main elements: the body and the neck. The body is in itself divided into three parts: two wooden surfaces unified by a side strip of wood. The upper surface also has an opening, a hole, which will be necessary to  the vent the amplification of the vibration caused bby the strings set in motion. The size of the body will define the colour of the tone and also the acoustic volume. The neck is the part that extends from the body and it also is divided into three main parts:
the actual neck, onto which the fretboard will be glued, the fretboard itself (the fretboard is usually made of a darker wood),and finally the headstock which is fitted with the tuning machines for pitch adjusting.
The fretboard is divided into sections known as frets (small metallic bars). Frets delimit notes according to a very precise set of rules which we shall look at more in detail later on. The standard number of strings is six, usually made of nylon. The neck is glued to the body of the instrument in a neck joint.
The strings are fixed onto the bridge (which is glued onto the upper surface of the body), placed onto the nut on the first fret and finally inserted in the tuning keys on the headstock.

The Folk guitar

Commonly known as Acoustic Guitar, this instrument differs from the classic guitar by having a larger body (although in recent years,  models with a smaller body have been produced), but mainly by having only metal strings. The fretboard also tends to be slimmer and tighter. The sound that this instrument emits is brighter and fuller when compared to its cousin (the Classic Guitar). We feel that it would be correct to state that although the term “Acoustic” is applied to the Folk Guitar, the Classic Guitar is also an acoustic instrument; this term infact generally describes the ability of a given element (in our casr the guitar) to amplify sound waves in a natural manner, and therefore without the help of electric pick-ups or amplifiers.

The electric guitar

This instrument is different from the other two types of guitar for a series of reasons: the wooden body is full, not hollow, it is smaller, and the way the sound is amplified is different. Amplification in this case is  given a particular type of magnetic microphone (pick-up), which in turn transport the sound signal to the amplifier. The possibilities offered by this type of instrument are various, thanks also to the fact that the number of combinations available between guitars, amplifiers and effects are virtually endless. Having said this, it is possible for Acoustic and Classic Guitars to be amplified, through the use of a specific type of pick-up (known as piezoelectric pick-ups). Aside from these three base models (Classic, Acoustic and Electric), one can find many variants, such as the Semiacoustic Guitar (also known as Jazz Guitar), which is recognizable by its hollow body but amplified using normal electric guitar pick-ups.